Composition for gas leakage detection

Abstract

To provide a composition for gas leakage detection that does not substantially include surfactant, and is excellent in foaming properties and excellent in spraying properties during application.SOLUTION: A composition for gas leakage detection contains water-soluble resin (excluding water-soluble resin in polymerization reaction under oxygen atmosphere) and water. The content of the water-soluble resin is 3 mass% or more and less than 5 mass% based on the total mass of the composition. The content of surfactant is less than 0.01 mass% based on the total mass of the composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a composition for detecting gas leakage.

Background Art

[0002] In order to detect gas leakage from joints of pipes through which gas flows by foaming, various compositions have been known. For example, Patent Document 1 describes a composition liquid for detecting gas leakage, which is characterized by dispersing a nonionic foaming agent, a nonionic foam stabilizer, an anionic rust inhibitor, a cationic rust inhibitor, and benzoic acid in water.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] Some compositions for detecting gas leakage contain surfactants to achieve foaming and other functions. However, for compositions for detecting gas leakage applied to resin pipe members and joint members, there is also a requirement for a composition that does not contain surfactants.

[0005] The present disclosure has been made in view of the above circumstances. The problem to be solved by one embodiment of the present disclosure is to provide a composition for detecting gas leakage that is excellent in foaming property and sprayability during application, and substantially free of surfactants.

Means for Solving the Problems

[0006] Specific means for solving the above problems include the following embodiments.

[0007] <1> It contains a water-soluble resin (excluding a water-soluble resin that undergoes a polymerization reaction in an oxygen atmosphere) and water, The content of the water-soluble resin is 3% by mass or more and less than 5% by mass based on the total mass of the composition, The content of the surfactant is less than 0.01% by mass based on the total mass of the composition, A composition for detecting gas leakage. <2> The composition for detecting gas leakage according to <1>, wherein the water-soluble resin contains polyvinyl alcohol. <3> Further, the composition for detecting gas leakage according to <1> or <2>, which contains an alkylene glycol. <4> The composition for detecting gas leakage according to <3>, wherein the alkylene glycol contains at least one of ethylene glycol and propylene glycol. <5> The composition for detecting gas leakage according to <3> or <4>, wherein the content of the alkylene glycol is 10% by mass to 50% by mass based on the total mass of the composition.

Advantages of the Invention

[0008] According to one embodiment of the present disclosure, it is possible to provide a composition for detecting gas leakage that is substantially free of a surfactant, has excellent foaming properties, and excellent spraying properties during application.

Modes for Carrying Out the Invention

[0009] Hereinafter, the present disclosure will be described in detail. The description of the requirements described below may be based on representative embodiments of the present disclosure, but the present disclosure is not limited to such embodiments, and can be implemented with appropriate modifications within the scope of the object of the present disclosure.

[0010] In the present disclosure, a numerical range indicated using "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

[0011] In the present disclosure, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the multiple components present in the composition.

[0012] In the present disclosure, the combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, unless otherwise specified, the molecular weight of a compound having a molecular weight distribution is the weight average molecular weight (Mw; the same hereinafter).

[0013] (Composition for gas leak detection) The composition for gas leak detection according to the present disclosure contains a water-soluble resin (excluding the water-soluble resin that undergoes a polymerization reaction in an oxygen atmosphere) and water, the content of the water-soluble resin is 3% by mass or more and less than 5% by mass based on the total mass of the composition, and the content of the surfactant is less than 0.01% by mass based on the total mass of the composition.

[0014] The composition for gas leak detection according to the present disclosure is substantially free of a surfactant, has excellent foaming properties, and excellent spraying properties during application.

[0015] (Water-soluble resin) The composition for gas leak detection according to the present disclosure contains a water-soluble resin. However, the water-soluble resin in the present disclosure does not include the water-soluble resin that undergoes a polymerization reaction in an oxygen atmosphere.

[0016] In the present disclosure, "water-soluble resin" means a resin having a solubility of 0.1 g or more in 100 g of water at pH 7.0 with a liquid temperature of 22°C.

[0017] In the gas leak detection composition according to the present disclosure, the content of the water-soluble resin is 3% by mass or more and less than 5% by mass, preferably 3% by mass or more and 4% by mass or less, based on the total mass of the composition. When the content of the water-soluble resin is 3% by mass or more and less than 5% by mass based on the total mass of the composition, the gas leak detection composition according to the present disclosure is excellent in both foaming property and sprayability. On the other hand, when the content of the water-soluble resin is less than 3% by mass based on the total mass of the composition, the gas leak detection composition cannot obtain foaming property, and when the content of the water-soluble resin is 5% by mass or more based on the total mass of the composition, the gas leak detection composition is inferior in sprayability.

[0018] The gas leak detection composition according to the present disclosure may contain only one kind of water-soluble resin or two or more kinds of water-soluble resins.

[0019] Examples of the water-soluble resin include polyvinyl alcohol-based resins (e.g., polyvinyl alcohol), polyacrylamide resins, polyethylene oxide resins, sodium polyacrylate, water-soluble alkyd resins, water-soluble modified alkyd resins, water-soluble epoxy ester resins, water-soluble acrylic resins, and water-soluble melamine resins.

[0020] From the viewpoints of foaming property and sprayability at normal temperature (23°C) and low temperature environments, the gas leak detection composition according to the present disclosure preferably contains polyvinyl alcohol as the water-soluble resin. In one aspect, the gas leak detection composition according to the present disclosure may contain only polyvinyl alcohol as the water-soluble resin.

[0021] The polyvinyl alcohol is not particularly limited as long as it can be applied to the gas leak detection composition, and it may be selected in consideration of foaming property and sprayability at normal temperature (23°C) and low temperature environments. The polyvinyl alcohol may be a synthetic product or a commercially available product. Examples of commercially available polyvinyl alcohols include polyvinyl alcohols marketed under the trade name Poval (specifically, the Kuraray Poval series manufactured by Kuraray Co., Ltd., the J-Poval series manufactured by Nippon Vinyl Alcohol & Poval Co., Ltd., the Denka Poval series manufactured by Denka Co., Ltd., etc.), the Gosenol series manufactured by Mitsubishi Chemical Corporation, and the like.

[0022] From the water-soluble resins contained in the gas leak detection composition according to the present disclosure, water-soluble resins that polymerize in an oxygen atmosphere are excluded. Examples of water-soluble resins that polymerize in an oxygen atmosphere include water-soluble alkyd resins, water-soluble modified alkyd resins, water-soluble epoxy ester resins, water-soluble acrylic resins, and water-soluble melamine resins.

[0023] <Alkylene glycol> From the viewpoint of achieving both freeze suppression and sprayability in a low-temperature environment (for example, 0°C or lower), the gas leak detection composition according to the present disclosure preferably further contains an alkylene glycol. The gas leak detection composition according to the present disclosure may contain only one type of alkylene glycol or two or more types thereof.

[0024] Examples of alkylene glycols include ethylene glycol, propylene glycol, 1,4-butanediol, and diethylene glycol.

[0025] The alkylene glycol may be a synthetic product or a commercially available product.

[0026] As the alkylene glycol, it is preferable to contain at least one of ethylene glycol and propylene glycol, and it is more preferable to contain ethylene glycol. In one aspect, the gas leak detection composition according to the present disclosure may contain only ethylene glycol as the alkylene glycol.

[0027] In the gas leak detection composition according to the present disclosure, the content of alkylene glycol is preferably 10% by mass to 50% by mass, more preferably 10% by mass to 45% by mass, still more preferably 20% by mass to 45% by mass, and even more preferably 25% by mass to 45% by mass, based on the total mass of the composition.

[0028] <Surfactant> In the gas leak detection composition according to the present disclosure, the content of the surfactant is less than 0.01% by mass based on the total mass of the composition.

[0029] The fact that the content of the surfactant is less than 0.01% by mass based on the total mass of the composition means that the gas leak detection composition according to the present disclosure substantially does not contain a surfactant. In other words, substantially not containing a surfactant means that although not intentionally containing a surfactant, the presence of less than 0.01% by mass of the surfactant that is unavoidably mixed in is allowed. In the gas leak detection composition according to the present disclosure, the content of the surfactant is preferably 0% by mass based on the total mass of the composition.

[0030] A surfactant refers to a substance having a part (hydrophilic group) that is easily compatible with water and a part (lipophilic group and hydrophobic group) that is easily compatible with oil in the molecule, and has an action of weakening the surface tension.

[0031] Since the content of the surfactant is less than 0.01% by mass based on the total mass of the composition, the gas leak detection composition according to the present disclosure can be applied without limitation to resin-made piping members and joint members.

[0032] <Water> The gas leak detection composition according to the present disclosure contains water. There is no particular limitation on the water as long as it is water used in the gas leak detection composition. For example, pure water, tap water, and well water can be mentioned.

[0033] The content of water is not particularly limited. For example, it is 1% by mass to 99% by mass based on the total mass of the composition.

[0034] <Other additives> The gas leak detection composition according to the present disclosure may contain a water-soluble resin, an alkylene glycol, and water, and optionally other additives, as long as the effects according to the present disclosure can be obtained.

[0035] Examples of other components include rust inhibitors, preservatives, dyes, fragrances, bittering agents (poison prevention agents), and the like.

[0036] (Preparation of gas leak detection composition) The gas leak detection composition according to the present disclosure can be prepared by mixing a water-soluble resin, an alkylene glycol, water, and optionally other additives used, and stirring with any stirring means while heating if necessary.

[0037] (Containing container) The prepared gas leak detection composition may be filled into a predetermined spray-type containing container. As the spray container, any spray container capable of filling the gas leak detection composition may be used, and examples thereof include a resin spray container.

[0038] (Method of using gas leak detection composition) The gas leak detection composition according to the present disclosure may be used in the same manner as a known gas leak detection composition by spray-applying it to a location where it is necessary to confirm the presence or absence of a gas leak and visually checking for foaming. Specifically, locations where it is necessary to confirm the presence or absence of a gas leak include, for example, pipe joint connection parts.

Examples

[0039] Hereinafter, the gas leak detection composition according to the present disclosure will be described more specifically by way of examples. However, the present disclosure is not limited to the following examples as long as the gist thereof is not exceeded.

[0040] [Examples A1 to A2] Each component was mixed in the amounts shown in Composition A below, and the gas leak detection compositions of Examples A1 and A2 were prepared respectively.

[0041] <Composition A> · Polyvinyl alcohol (Product name: Denka Poval B-17, manufactured by Denka Co., Ltd., water-soluble resin) … the amount (mass%) described in Table 1 · Water … the remaining amount to make 100 mass% of the whole gas leak detection composition In Table 1, the content of polyvinyl alcohol was described in the column of "PVA content".

[0042] [Evaluation 1] The gas leak detection compositions prepared in Examples A1 to A2 were each filled with 100 g into a spray container (Product name: Push-type spray container, manufactured by AS ONE Corporation, capacity: 100 mL) to prepare container-packed samples. Using the prepared container-packed samples, the foaming property and sprayability were evaluated.

[0043] <Foaming property> Using each of the container-packed samples of Examples A1 to A2, the foaming property was evaluated according to the following evaluation method and evaluation criteria. The results are shown in Table 1.

[0044] = Evaluation method = A polybutene pipe with a pseudo leak point created by attaching fibers or the like was inserted into a resin joint and the end was sealed to make a test piece. This test piece was pressurized with an air pressure of 0.6 MPa. In an environment of 23°C, the gas leak detection composition prepared from the container-packed sample was sprayed onto the connection part between the polybutene pipe and the resin joint of the pressurized test piece, and the presence or absence of foaming was visually confirmed. = Evaluation criteria = Y: Foaming N: No foaming

[0045] <Sprayability> Using each of the container-packed samples of Examples A to A2, the sprayability at 0°C and 23°C was evaluated according to the following evaluation method and evaluation criteria, and the results are shown in Table 1.

[0046] =Evaluation Method= One sample of each of the container-packed samples of Examples A1 to A2 was allowed to stand in an environment at 0°C for 24 hours each. Separately, one sample of each of the container-packed samples of Examples A1 to A2 was allowed to stand in an environment at 23°C for 24 hours each. For each of the container-packed samples after standing, the push part of the spray container was pushed down with the index finger and evaluated based on the following evaluation criteria. =Evaluation Criteria= A: It can be sprayed easily. B: A weight is felt when pushing down the push part, but it can be sprayed. C: It cannot be sprayed.

[0047] [Examples A3, Comparative Examples 1 to 2] Each component was mixed in the amounts shown in Composition A above to prepare the gas leak detection compositions of Example A3, Comparative Examples 1 and 2, respectively.

[0048] Using the container-packed samples of Example A3 and Comparative Examples 1 to 2, the results that would be obtained when performing the evaluations of <foaming property> and <sprayability> shown in the above [Evaluation 1] were predicted based on the inventor's prior knowledge and are shown in Table 1.

[0049]

Table 1

[0050] [Examples B1 to B5] Each component was mixed in the amounts shown in the following Composition B to prepare the gas leak detection compositions of Examples B1 to B5, respectively.

[0051] <Composition B> · Polyvinyl alcohol (product name: Denka Poval B-17, manufactured by Denka Co., Ltd., water-soluble resin) … 4% by mass · Ethylene glycol (product name: Ethylene Glycol Special Grade, manufactured by Hayashi Pure Chemical Industries, Ltd., alkylene glycol) … the amount (% by mass) described in Table 2 · Water... The remaining amount that makes up 100% by mass of the entire gas leak detection composition In Table 1, the content of ethylene glycol is described in the column of "ethylene glycol content".

[0052] [Evaluation 2] <Freezing temperature (°C)> The freezing temperatures (°C) of the gas leak detection compositions prepared in Examples B1 to B5 were calculated. The calculation method is as follows. The results are shown in Table 2.

[0053] =Calculation method of freezing temperature= The value of the freezing point depression ΔT’ (°C) calculated by the following formula (1) was taken as the freezing temperature (°C). ΔT’ = Kf × m... Formula (1) ΔT’: Freezing point depression Kf: Molal freezing point depression of water 1.85 m: Molality

[0054] <Sprayability> The gas leak detection compositions prepared in Examples B1 to B5 were each filled with 100 g into a spray container (product name: push-type spray container, manufactured by AS ONE Corporation, capacity: 100 mL) manufactured by AS ONE Corporation to prepare container-filled samples. Using one container-filled sample each of Examples B1 to B5, the sprayability at 0°C was evaluated in the same manner as in Example A1. The results are shown in Table 2.

[0055]

Table 2

[0056] From the above results, it can be seen that the gas leak detection compositions of the examples are excellent in foaming properties and sprayability during application without substantially containing a surfactant.

Claims

1. A composition for detecting gas leakage, which contains a water-soluble resin (excluding a water-soluble resin that undergoes a polymerization reaction in an oxygen atmosphere) and water, wherein the content of the water-soluble resin is 3% by mass or more and less than 5% by mass based on the total mass of the composition, and the content of the surfactant is less than 0.01% by mass based on the total mass of the composition.

2. The composition for detecting gas leakage according to claim 1, wherein the water-soluble resin contains polyvinyl alcohol.

3. The composition for detecting gas leakage according to claim 1 or claim 2, further containing an alkylene glycol.

4. The composition for detecting gas leakage according to claim 3, wherein the alkylene glycol contains at least one of ethylene glycol and propylene glycol.

5. The composition for detecting gas leakage according to claim 3, wherein the content of the alkylene glycol is 10% by mass to 50% by mass based on the total mass of the composition.

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